Valve-tube.



E. W. CALDWELL.

VALVE TUBE.

APPLICATION IILEDAPR. 19, 1912.

Patented Oct. 28, 1913.

WITNESSES 9 1; Q

EUGENE CALDWELL, OF NEW YORK, N. Y.

VALVE-TUBE.

Specification of Letters Patent.

Application filed April 19, 1912.

Patented Oct. 28,1913.

Serial No. 691,804.

To all ax/mm, it may concern Be it known that I, Eoonnn W. CALD- WELL, acitizen of the United States, and resident of the city, county, andState of New York, have made certain new and useful ImprovementsRelating to Valve-Tubes, of which the following is a specification,

. taken in connection with the accompanying drawing, which forms part ofthe same.

This lnvention relates especially to valve tubes of the Villard typeprovided with a cathode arranged to coact with cooperating regulatingmeans so as to automatically regulate the vacuum or condition of thetube and promote uniformity of operation. The high vacuum valve tube maybe provided for instance with a coiled or other large surface cathodehaving a portion capable of producing a concentrated or eifectivecathode stream when the tube gets into regulating condition because ofhigh vacuum or the like. In this way the cathode stream or heat ingeffects may act upon any cotiperating means capable of introducing intoor producing within the tube suitable gas or vapor to reduce the tubevacuum, for instance the cathode stream may impinge upon suitablydisposed gas generating material to liberate gas therefrom and regulatethe vacuum or other electrical discharge condition of the tube,preferably until it is restored to its normal critical condition inwhich this heating or regulating action no longer takes place but isimminent.

In the accompanying drawing showing in a somewhat diagrammatic mannerseveral illustrative embodiments of this invention, Figure 1 shows incentral section a form of Villard tube of this character. Fig. 2 howsanother form of tube; and Fig. 8 shows still another modification.

The tube may have a suitable body of any desired size and shape, and asindicated in Fig. 1, the substantially cylindrical tube body 1 may beconnected with the neck 2. The support 3 in this neck may hold inposition the end 4: of the cathode electrode which may be electricallyconnected with the terminal 17 projecting on the outside of the tube.The enlarged surface cathode may be formed of any suitable material andmay be given any desired contour, preferably com prising a focusingportion adapted to focus or concentrate the cathode stream underregulating conditions. For this purpose the cathode may be provided witha suitable focusing portion in the shape of the substantially sphericalcathode cup (5 which may be electrically connected with or supported onthe cathode in any desired way as by hemg connected on the end of thecathode coil 5 of aluminum wire or other suitable material. It isdesirable for some purposes to have the focusing portion of the cathodecomprise only a small portion of its effective area so as to secure amoderate regulating action when the tube requires regulation, althoughthis is not necessary in all cases. The focusing portion of the cathodemay cooperate in any desired way with suitably mounted means or materialfor reducing the tube vacuum which may, if desired, be located withinthe tube. As indicated the cathode cup may cooperate with a suitablecarrier ball 9 formed of porous or fibrous material, such as pureasbestos fiber wound or compacted into a ball and impregnated withsuitable gas generating material, such for instance as sodium orpotassium hydrate, or prclcrably sodium formate which has beenthoroughly dried. The carrier may be mounted in any desired way and asindicated the carrier ball 9 may be loosely mounted within a suitablespherical cavity in the holder 7 located, if desired, in acorrespoiuling recess 8 in the side of the tube so that the carrier ballmay move freely around in this cavity and bring different portions ofits surface into cooperation with the cathode cup which under regulatingconditions focuses the cathode stream 10 upon this carrier so that underthese conditions gas is evolved from the gas generating material and thetube vacuum is correspondingly lowered. The tube may as indicated beprovided with a suitable connection 10 communicating with the restrictedanode passage 11. and the anode chamber 12. The small surface anode 1%within this chamber may be held in position by the support 13 andconnected by the metallic connection 15 with the terminal 16 on theoutside of the tube.

It seems desirable for uniform operation that these valve tubes shouldbe operated at about the critical condition at which the vacuum,resistance and so forth are such as to produce no substantial disclurgeregulating action such as concentration of the cathode stream or heatingeffects on the gas by a. relatively slight increase in the vacuum,

. resistance and so forth, 'so' that the tube passes quickly from thecritical condition to the regulating condition in which there issufficient focusing or concentration of the the reduced end 5970f thetube.

ing a suitable operating weight 61 on the cathode stream to produceheating effects and evolve gas from the gas generating material to lowerthe vacuum. In this way the automatic regulating act-ion of the tube isquite uniform and gradual, especially when only a relatively smallportion of the cathode surface has such focusing or regulating action.In the form of tube illus-H trated in Fig. 1 when for instance thevacuum in the tube rises to such extent as to bring the tube intoregulating condition the cathode stream is concentrated suificientlyupon the carrier to produce heating eil'ects in the gasgenerating'rnatcrial therein sufi r' cient to gradually evolve gas andautomatically reduce the vacuums-rid restore the tube to the criticalCOIldllZlOn in which the oath ode stream is no longer suficientlyconcentrated to produce these regulating efiects. Reliable operation ofthese tubes can thus be secured especially when a number of them areused in series to secure substantially therethrough for therectification of high potential alternating currents of relatively of afocusing portion which may be given the form of a concave cup 62 whichmay have a central hole 63 and be supported by the stem 5% mounted inlateral extension 69 of the tube. Under normal conditions of desirablelow vacuum the cathode stream is dispersed and the tube has the normalvalve action. When, however, the tube vacuum becomes undesirably highthe cathode stream is concentrated so as to strike the salt 57 mountedupon a suitable support 177 so as to evolve sufiicient gas to reduce thevacuum and again disperse the cathode stream and stop the evolutionofgas. The support 17 7 may be made adjustable within the tube by beingmounted on a threaded stem 84 which may cooperate with a suitable nut16% mounted in the tubular glass support 159 in By securstem 6% therotation of the threaded stem and consequent screw adjustment of thesupport 17 7- maybe secured by holding the tube unidirectionalelectrical discharges with its axis substantially horizontal and,rotating it to the desired extent.

Still another form of self-regulating valve tube is indicated iIiFi'g. 3in which the enlarged cathode 71 may be given the, concave formindicated and be mounted on the metallicstem 73 in the extension 59 ofthe tube. The anode 58 is mounted in the usual way in the other end ofthetube beyond the V restricted passage or neck 157 'of the anodechamber 60 and may have electrically connected therewith by the wire 72or otherwise a suitable elect-rode. 66 arranged in a suitable depression70 in the tube and surrounded with a mass of high insulation 85.

When the vacuum in the tube becomes undesirubly high the potentialdifference between the cathode and the anode is correspondinglyincreased and this increases the elec trical attraction between thecathode stream 68 and the electrode 66 so as to attract the cathode.stream toward the electrode and cause its impingement upon the gasproducing salt 57 on a suitable support .67 mounted in the tube. W'hen,however, the vacuum is sufliciently reduced to restore the tube to itsnormal critical condition, the cathode stream no longer impingessufiiciently on the sup-' 7 port to cause further action on the salt carried thereby.

Having described the invention in this case which contains subjectmattertaken from my copending application, Serial No. 638,628efiled July 15,1911 of which thiscase is a continuation, in connection with a number ofillustrative embodiments, forms, proportions, materials, arrangementsand connections of parts, to the details of which dis closure theinvention is not of course to be limited, what is claimed as new andwhat is desired to be secured by Letters Patent, is set forth in theappended claims.

What I claim is l. The self-regulating Villard type valve tubecomprising a vacuum tube provided with a restricted anode passage andcommunicating small areaanode chamber hav ing an anode mounted therein,a large sur face cathode mounted within said tube and comprising acathode coil and a focusing portion in the form or a substantiallyspherical cathode cup, a carrier ball formed of porous fibrous asbestosimpregnated with gas generating material to cooperate with thefocusing-portion of said cathode and a holder having a substantiallyspherical cavity in which said carrier ball is loosely mounted to bringdifierent portions of the gas generating material into cotiperatio-nwith the focusing portion of the cathode and to generate gas by thecathode stream produced during the discharge regulating condition ofthegzube.

2. The self-regulating Villard type valve tube comprising a vacuum tube-.provided with a small area anode chamber having an anode mountedtherein, a large surface cathode mounted within said tube and comprisinga focusing portion in the form of a cathode cup, a carrier ball formedof po rous. fibrous asbestos impregnated with gas enerating material tocoiiperate with the ocusing portion of said cathode and a holder havinga substantially spherical cavity in which said carrier ball is looselymounted to bring different portions of the gas generating material intocooperation with the focusing portion of the cathode and to generate gasby the cathode stream produced during the discharge regulating conditionof the tube.

3. The self-regulating Villard type valve tube comprising a vacuum tubeprovided with a small area anode chamber having an anode mountedtherein, a large surface cathode mounted within said tube and comprisinga focusing portion, a carrier ball formedof porous material impregnatedwith gas generating material to cooperate with the focusing portion ofsaid cathode and a a holder having a cavity in which said carrier ballis loosely mounted tobring different portions of the gas generatingmaterial into cooperation with the focusing portion of the cathode andto generate gas by the cathode stream produced during the dischargeregulating condition of the tube.

4. The self-regulating Villard type valve tube comprising a vacuum tube,an anode mounted in the tube, a large surface cathode mounted within thetube and comprising a focusing portion, acarrier impregnated with gasgenerating material to co'iiperate With the focusin portion of saidcathode and a holder in w ich said carrier is loosely mounted to bringdifferent portions of the gas generating material into cooperation withthe focusing portion of the cathode and to generate gas by the cathodestream produced during the discharge regulating condition of the tube.

5. The self-regulating Villard type valve tube comprising a vacuummounted in the tube, a large surface cathode mounted within the tube andgas generating material in the tube to coiiperate with said cathode andto generate as by the cathode stream produced during tie dischargeregulatin condition of the tube.

6. he self-regulating Villard type valve tube, an anode tube comprisinga vacuum tube provided with a small area anode chamber having an anodemounted therein, a large surface cathode mounted within said tube andcomprising a focusing portion in the form of a cathode cup and gasgenerating material including sodium formate to cooperate with thefocusing portionof said cathode and to generate gas by the cathodestream produced during the discharge regulating condition of the tubeand thereby restore the tube to the critical condition in which thesubstantial concentration of the cathode stream and heating effects arenot produced.

-7. The self-regulating Villard type valve tube comprising a vacuum tubeprovided with a small area anode chamber having an anode mountedtherein, a large surface cathode mounted Within said tube and comprisinga focusing portion and gas generating material to coiiperatewith thefocusing portion of said cathode and to generate gas during thedischarge regulating condition of the tube and thereby restore the tubeto the critical condition in which substantial heating effects are notproduced.

8. The self-regulating Villard type Valve tube comprising a vacuum tubeprovided with a small area anode chamber having an anode mountedtherein, a large surface cathode mounted within said tube and comprisinga focusing portion and means c ooperating with the focusing portion ofsaid cathode to reduce the vacuum of said tube a when the concentratedstream cooperates with said means during the discharge regulatingcondition of the tube and to thereby restore the tube to the criticalcondition in which substantial concentration of the cathode stream andheating effects are not produced.

9. The self-registering Villard type valve tube comprising a vacuum tubehaving ananode mounted therein, a large surface cathode mounted withinsaid tube and means cooperating with said cathode to reduce the vacuumof said tube during the discharge regulating condition of the tube andthereby restore the tube to the critical condition in which substantialheating effects are not produced.

EUGENE W. CALDWELL. Witnesses:

S. CLAIRE KELLY, THOMAS J. BIKER.

